Trigger actuated switch device



C. J. FRENZEL TRIGGER ACTUATED SWITCH DEVICE Feb. 3, 1970 2 Sheets-Sheet1 Original Filed Dec.

mvE/vron CARL J. FRENZEL Bu/wzL ATT'YS Feb. 3, 1970 c. J. FRENzl-:L

TRIGGER ACTUATED SWITCH DEVICE 2 Sheets-Sheet z Original Filed Deo. 27.1965 IN VEN TOR CARL J. FRENZEL Bvd/@ivm ATT'YS.

United States Patent O" 26,781 TRIGGER ACTUATED SWITCH DEVICE Carl J.Frenzel, Chicago, Ill., assignor to Skil Corporation, Chicago, Ill., acorporation of Delaware Original No. 3,309,484, dated Mar. 14, 1967,Ser. No. 516,331, Dec. 27, 1965. Application for reissue Apr. 4, 1968,Ser. No. 719,792

Int. CI. H01h 9/06, 13/08, 21/10 U.S. Cl. 200-157 14 Claims Matterenclosed in heavy brackets appears in the original patent but forms nopart of this reissue specification; matter printed in italics indicatesthe additions made by reissue.

ABSTRACT F THE DISCLOSURE The trigger carries a rotatable knob. Rotationof this knob moves an adjustable stop on the trigger which is arrangedfor abutting engagement with a fixed stop on the switch casing therebylo control the stroke of trigger movement. The trigger may be locked inany depressed position thereof wherein the adjustable stop is inabutting engagement with the fixed stop.

This invention relates to trigger actuated switch devices for portabletools, and more particularly the invention relates to a new and improvedtrigger operated switch device including adjustable stop means forvarying the stroke of the trigger and further including rocking meansfor locking the trigger aganst the adjustable stop means in allpositions of the latter.

By way of background, reference is made to Gawron Patent No. 3,209,228,assigned to the assignee of the present invention. The Gawron patentdiscloses and claims a variable speed control system for portable powertools, such as power drills, which system includes a silicon controlledrectifier circuit having a variable resistor or potentiometer operatedby the tool trigger. In this system, the speed of the tool motor isincreased as the tool trigger is depressed or squeezed. By way ofexample, the speed of the tool motor may be gradually varied from 0 to2,000 r.p.m.

In performing some operations using a power tool provided with a speedcontrol system, such as the aforementioned Gawron system, it may bedesirable to operate the tool a number of times, in a consecutivemanner, at a predetermined speed, say 1,000 r.p.m. and/or it may bedesirable to operate the tool for an extended period of time at apredetermined constant speed. The present invention provides a triggeractuated switch device for use with a tool and speed control system ofthe type described, which switch device includes an adjustable stop forvarying the stroke of the trigger to allow operation of the associatedtool at a desired or predetermined speed by squeezing the trigger untilit is stopped, and which switch device further includes locking meansfor locking the trigger at any and all of its stopped positions.

A primary object of the present invention is the provision of a triggeractuated switch device including unique, manually operable means foradjusting the stroke of the trigger.

Another object of the present invention is the provision of a triggeractuated switch device having adjustable stop means for varying thestroke of the trigger and further including locking means for releasablylocking the trigger in any and all of its stopped positions.

Still another object of the present invention is the provision of atrigger actuated switch device capable of fulfilling the aforementionedobjects and also being capable of providing precision-like control ofthe tool trigger Re. 26,781 Ressuted Feb. 3, 1970 ice thereby to providecorresponding control of the speed of the associated motor.

These and other objects and adavntages of the invention will becomeapparent from the following specification disclosing a preferredembodiment of the invention which is illustrated in the accompanyingdrawings wheremg:

FIG. 1 is a partially sectioned side elevation of one embodiment of thetrigger actuated switch device of the present invention showing the samemounted in a portable tool, such as a power drill;

FIG. 2 is a partially sectioned top plan view of the switch showing thetrigger in its fully extended or ofi position;

FIG. 3 is a partially sectioned top plan view of the switch deviceshowing the trigger in one of its stopped positions;

FIG. 4 is a partially sectioned side elevation of the switch device inthe configuration illustrated in FIG. 3; and

FIG. 5 is an exploded, perspective view of the trigger operated switchdevice.

Referring now to the drawings, the illustrated embodiment of the triggeractuated switch device of this invention includes a trigger 10 ofunitary construction having a finger engageable portion 10a and a stemportion 10b. The switch unit further includes a casing 11 having a sheetmetal member 12 defining a guideway slidably receiving stem portion 10bof the trigger. Stem portion 10b includes or carries an upwardlyextending projection or button 14 which is received in an elongated slot15 formed in the top wall of casing 12. Abutting engagement of thebutton 14 with opposite ends of the slot 15 determines the maximumstroke of the trigger. A spring 16 contained within the casing 12yieldably urges the trigger l0 to its outermost or extended position,i.e., the off position, which is established by abutting engagement ofbutton 14 with the front end of slot 15 (see FIG. l). One end of spring16 abuts an end plate 18 of the casing 12, and the other end of thespring is received within a cavity 19 formed in trigger stem 10b.

Casing 11 includes suitable means 20 defining a compartment adapted toreceive the various components of a control system, such as the variablespeed control system disclosed and claimed in the aforementioned Gawronpatent. As mentioned above, the Gawron system includes a variableresistor which is operated by trigger movement. By way of example, thisvariable resistor may consist of a contact carried by trigger stem 10band slidable along a rectilinear contact strip of resistance material(not shown) supported by member 20 so that the resistance is changed bymovement of the trigger. As explained in the aforementioned Gawronpatent, this change of resistance causes a corresponding change in thespeed of the tool motor. Preferably, stem 10b and member 20 will alsoinclude cooperating contacts and contact strips constituting the onofi"and by-pass' switches referred to in the above mentioned Gawron patent.

The linger engageable portion 10a of the trigger includes a recess 22,and the stem portion 10b of the trigger includes a recess 23. Recesses22 and 23 are in communication with each other. A lug or nut 24 isreceived within recesses 22, 23. Recess 22 has opposite side walls, andrecess 23 has one side wall, all of which side walls act to preventrotation of lug [24] as will be come apparent from the followingspecification. Lug 24 includes a threaded through bore 25. A catch plate26, either integral with plate 24 or suitably secured thereto, includesan opening 27.

Finger engageable portion 10a of the trigger has a cavity or cut-out 29at the front thereof. Portion 10a of the trigger also has a bore 30 withthe central axis thereof extending parallel with the direction oftrigger movement. Bore opens at one [end] of its ends into recess 22 andopens at its other end into the cavity or cut-out 29.

An adjustment screw 32 has a cylindrical portion 33 rotatably receivedin bore 30 of trigger portion 10a. This cylindrical portion includes anannular groove 33a. Trigger portion a includes a cross bore 34 in whicha pin 35 is reveived. As noted in FIG. l, the pin 35 extends intoannular groove 33a of the adjustment screw. It will be apparent that theadjustment screw 32 may be rotated relative to the trigger but [that]axial movement between the adjustment screw and the trigger is preventedby the pin 35. The adjustment screw further includes a knurled knob orbutton portion 37 which is received within the cut-out or cavity 29 ofthe trigger 10.

The adjustment screw 32 has a threaded shank portion 38 threadinglyreceived in the threaded opening 25 of the lug 24. This threaded portionof the shank actually serves to support the lug on the trigger. Asmentioned above, the various side walls of recesses 22 and 23 preventrotation of the [lug] 24. Therefore, it will be apparent that uponrotation of the adjustment screw 32, lug 24 will be moved along theshank 38 i.e., relative to the trigger, depending on the direction ofrotation of the adjustment screw 32. Movement of lug 24 causes movementof plate 26 as these two members are either integral or suitably securedtogether.

Lug 24 includes a lip or abutment face 24a, which face is arranged forabutting engagement with edge 12a of the casing `(see FIGS. 4 4and 5).Abutting engagement of face 24a and 12a stops the trigger, i.e., limitsthe amount of movement or the stroke thereof.

One side wall of the casing 12 includes a bent-out portion 12b (FIGS. 2and 3) having an opening 39 therein. A sleeve 40 includes areduced-in-diameter portion 40a at one end thereof, which portion isfitted within the opening 39. This engagement between opening 39 andreducedin-diameter portion 40a serves as a means for mounting the sleeve40 on the casing 12. Sleeve 40 includes a first bore 40h and a coaxial,largerin-diameter bore 40e. A pin 42 having a head 42a is slidablymounted in bore 40h. A button 43 is secured to the outer end of pin 42,which button is slidably reoeived within bore 40C. A spring 44 encirclespin 42. One end of the spring abuts an annular shoulder between bores40h, 40C, and the other end of the Spring abuts the inner end of button43.

The spring 44 acts to urge pin 42 and button 43 outwardly with the head42a of the pin against reduced-indiameter end 40a of the sleeve (seeFIG. 3). As will be explained hereinbelow, pin 42 is adapted to beinserted in opening 27 of the plate 26 for locking the trigger in itsfully depressed or stopped position which is determined by abuttingengagement of button 14 with the inner end of slot and in any stoppedposition determined by abutting engagement of face 24a with casing edge12a.

For purposes of the following discussion of the operation of the triggeractuated switch device of this invention, assume that the same ismounted within the pistol grip portion of a portable tool, such as apower drill. The pistol grip portion of a. power tool is fragmentarilyillustrated in FIG. 1 and designated by the numeral 45. When the triggeroperated switch unit is mounted in the handle grip portion of the tool,trigger portion 10a extends outwardly through an opening 46 in the toolhousing thereby to permit manual depression of the trigger. The toolhousing also includes an opening (not shown) for accommodating sleeve 40of the locking mechanism. Assume further, for purposes of illustrationonly, that the compartment contains the various components of thevariable speed control system covered in the aforesaid Gawron patent.The trigger 10 will be connected to the variable resistor in Suchcircuit so that as the trigger is depressed, the speed of the associatedtool motor is correspondingly increased.

If it is not desired to use the adjustable stop and locking feature ofthe present invention, knurled knob 37 of the adjustment screw 32 isrotated for moving lug 24 to the left until it is fully seated withinthe recess 22 (FIGS. l and 2). In this position of the lug 24, thetrigger may be squeezed or depressed until the button 14 comes intoabutting engagement with the inner end of slot 15. With the trigger inthis position, i.e., its maximum position, maximum speed of theassociated tool is obtained. When trigger 10 is depressed as justexplained, face 24a may be in abutting engagement with edge 12a or theremay be a slight space between these two surfaces.

lf it is desired to operate the tool motor at a speed somewhat less thanits maximum speed, knob 37 of the adjustment screw is rotated forrunning lug 24 to the right as illustrated in the drawings. Experiencein using a tool incorporating the present invention will enable theoperator to know approximately how many revolutions of the knob 37 arerequired to bring about the desired speed of the tool. Of course,indicia (not shown) on either the button 37 or the trigger or both couldbe provided to indicate various speeds or trigger positions. After thelug 24 has been run along the threaded portion 38 of the adjustmentscrew by rotating the same, the trigger is squeezed until face 24a comesinto abutting engagement with edge 12a thereby establishing a certaincontrol position of the trigger. If the speed of the motor is not asdesired, the trigger can be released and the knob 37 rotated in onedirection or the other in order to change the speed of the motor whenthe trigger is again depressed thereby establishing another control p0-siton of the trigger.

When face 24a is brought into abutting engagement with edge 12a of thecasing by squeezing of the trigger, opening 27 in plate 26 is inalignment with pin 42. Accordingly, if it is desired to lock the triggerin its stopped position, i.e., its position wherein face 24a is inabutting engagement with edge 12a, button 43 is depressed therebycausing head 42a of the pin to be forced through the opening 27 in theplate 26. Releasing of the trigger will allow the spring 16 to force thetrigger slightly forwardly until the trailing portion of the opening 27engages the shank of the pin 42 adjacent the head 42a. The trigger isunlocked by squeezing the trigger slightly until the opening 27 isbrought into alignment with head 42a; when the trigger is in thisposition, spring 44 will act to force pin 42 outwardly clear of theplate 26, thereby releasing the trigger. It should also be mentionedthat when lug 24 is in its forwardmost position relative to the triggerand when the trigger is depressed its maximum amount determined bybutton 14 abutting the innermost end of the slot 15, the opening 27 isin alignment with pin 42 thereby permitting the trigger to be locked inits maximum depressed position. Locking the trigger in this positionpermits continuous operation of the tool at its maximum speed.

It should be noted that if the trigger is depressed and locked againstmovement by pin 42, rotation of the adjustment button 37 will then causemovement of the trigger and, accordingly, a change in the speed of theassociated tool motor. This result occurs because the engagement of thepin 42 in the opening 27 prevents axial movement of the lug 24.Therefore, when the adjustment screw 32 is rotated, the latter and thetrigger itself are moved. When the trigger is locked by the pin 42 andthe button 37 rotated as just described, the button 37 acts as a vernierto provide precise trigger control and therefore corresponding speedcontrol for the associated motor.

It should be apparent that the present invention provides a unique meansfor adjustment or varying the stroke of the tool trigger and for lockingthe tool trigger when it is squeezed and stopped by operation of theadjustable stop. The knob 37 can be readily manipulated; this knob doesnot require an additional opening in the power tool housing as theformer is contained within the tool trigger. As explained above, whenthe locking mechanism is actuated rst and the adjustment screw thenrotated, the latter acts as a vernier for providing precision-likecontrol of the speed of the associated tool motor.

While the invention has been shown in but one form, it will be obviousto those skilled in the art that it is not to be so limited. On thecontrary, the invention is susceptible of various forms andmodifications without departing from the spirit and scope of theappended claims.

I claim:

1. In a portable tool having a trigger receiving housing aperture,wherein the tool is of the type adapted to contain a control systemcapable of varying the speed of the tool motor in response to the amountof trigger movement, a trigger actuated switch device for mounting insaid tool with the trigger extending through said aperture for manualdepression, said switch device comprising, a casing, a trigger mountedby the casing for oscillating movement, resilient means carried by thecasing and engaged with the trigger for urging the same to its extendedposition, said trigger including guide means extending in parallelrelation with the direction of trigger movement, lug means carried bysaid trigger and engaged with said guide means for movement in eitherdirection therealong, a manually operable adjustment means including amember rotatably carried by the trigger and engaged with said lug meansfor moving the same in either direction along said path of movementthereof, and abutment means on said casing arranged to be engaged bysaid lug means upon depression of the trigger thereby to limit theamount of movement of the latter for establishing a selected speed ofthe tool motor.

2. In a portable tool having a trigger receiving housing aperture,wherein the tool is of the type having a control system capable ofvarying the speed of the tool motor in response to the amount of triggermovement, a trigger actuated electric switch device for mounting in saidtool with the trigger extending through said aperture for manualdepression, said switch device comprising, a casing and a triggermounted thereby for oscillating movement, said device also includingresilient means interposed between said casing and said trigger forurging the latter to its extended position, abutment means carried bysaid casing, adjustment means carried by said trigger including anelement movable relative to the latter to and away from said abutmentmeans along a path corresponding to the path of movement of the trigger,said element being arranged to abut said abutment means upon depressionof the trigger thereby to limit the amount of movement of the latter forestablishing a selected speed of the tool motor, said device includinglocking means engageable with said element for locking said trigger inany one of its positions determined by engagement of said element withsaid abutment means.

3. The switch device according to claim 1 wherein said adjustment meansincludes a button rotatably mounted in a bore in said trigger and beingexposed for manual control.

4. The switch device according to claim 3 wherein said adjustment meansfurther includes a screw connected to said button for rotation thereby,and wherein said lug means includes a member having an openingthreadingly receiving said screw.

5. The switch device according to claim 1 further defined by, triggerlocking means including a locking pin, which locking means is mounted onsaid casing for extending through a bore in the tool housing thereby toexpose said pin for manual depression, catch means carried by said lugmeans and adapted to be releasably locked by said pin when the catchmeans is aligned with the pin.

6. A trigger actuated switch device for mounting 1n the housing of aportable tool with the trigger extending through a housing aperture formanual depression, wherein the tool is of the type adapted to contain acontrol system capable of varying the speed of the tool motor inresponse to the amount of trigger movement, said switch devicecomprising, a casing, a trigger mounted by the casing for reciprocatingmovement relative thereto, resilient means carried by the casing andengaged with the trigger for urging the same to its extended position,said trigger including means defining a guideway extending parallel withthe direction of trigger movement, a lug in said guideway and adaptedfor movement in either direction therealong, which lug includes athreaded opening extending parallel with the direction of movement ofthe lug, said trigger including a bore extending parallel with thedirection of trigger movement and opening at the front of said trigger,adjustment screw means rotatably mounted in said bore and having aportion thereof disposed exteriorly of said trigger adjacent the frontthereof, means for preventing axial movement of said adjustment Screwmeans relative to said trigger, said adjustment screw means beingthreadingly engaged in the opening of said lug for moving the latter inresponse to rotation of the former, and abutment means on said casingarranged to be engaged by said lug upon depression of the triggerthereby to limit the amount of movement of the latter.

7. The switch device according to claim 6 further defined by, triggerlocking means including a locking pin, which locking means is mounted onsaid casing for extending through a bore in the tool housing thereby toexpose said pin for manual depression, catch means carried by said lugand adapted to be releasably locked by said pin when the catch means isaligned with the pin. 8. A trigger actuated switch device for mountingin the housing of a portable tool with the trigger extending through ahousing aperture for manual depression, wherein the tool is of the typeadapted to contain a control system capable of varying the speed of thetool motor in response to the amount of trigger movement, said switchdev ice comprising, a casing, a trigger mounted by the casing forreciprocal movement relative thereto, resilient means carried by thecasing and engaged with the trigger .for urging the same to its extendedposition, Said trigger including means defining a guideway extendingparallel with the direction of trigger movement, a lug in said guidewayand adapted for movement in either direction therealong, which lugincludes a threaded opening extending parallel with the direction ofmovement of the lug, said trigger including a cavity at the frontthereof, said trigger further including a bore extending parallel withthe'direction of trigger movement and opening into said cavity, anadjustment screw rotatably mounted in said bore and having the headthereof received within said cavity, means for preventing axial movementof said adjustment screw relative to the trigger, said adjustment screwhaving a threaded portion threadingly engaged in the opening of said lugfor moving the latter in response to rotation of the former, abutmentmeans on said casing arranged to be engaged by said lug upon depressionof the trigger thereby to limit the amount of movement of the latter,trigger locking means including a locking pin, which locking means ismounted on said casing for extending through a bore in the tool housingthereby to expose said pin for manual depression, catch means carried bysaid lug and adapted to be releasably locked by said pin when the catchmeans is aligned with the pin.

l9. The switch device according to claim 8 wherein said catch meansincludes a plate having an opening therein for receiving said pin.

10. The switch device according to claim 8 further delined by, saidcasing including a compartment adapted to receive the components of asolid state speed control circuit.

11. For use with a portable tool having a housing with atrigger-receiving aperture, wherein such tool is of the type adapted touse a control system capable of varying the speed of the tool motor inresponse to the amount of trigger movement, a trigger actuated switchdevice for mounting in said housing with the trigger extending throughsaid aperture for manual depression, said switch device comprising, acasing, a trigger mounted by the casing for oscillating movementrelative thereto, resilient means interposed between said trigger andsaid casing for urging the former in one direction of movement thereofto an extended position, a xed abutment surface on said casing and amovable abutment surface on said trigger for movement relative thereto,manual adjustment means carried by said trigger and connected with saidmovable abutment surface for moving the same to one position permittingsaid trigger to be moved a trst disance in its other direction therebyestablishing a first control position, which adjustment means also serveto move said movable abutment surface to at least one other position,whereby the same, upon movement of said trigger in said other direction,abuts said yxed abutment surface thereby to limit the amount of movementof said trigger in the other direction to a distance less than saidfirst distance thereby establishing a second control position.

12. The trigger actuated switch device according to ciaim Il furtherdefined by, manually operated locking means on said casing andcooperating catch means on said trigger for locking the latter in bothits first and second control positions.

13. The trigger actuated switch device according to claim 11 furtherdefined by, said trigger being mounted for reciprocal movement andincluding a bore extending in parallel relation with its path ofmovement, said adjustment means including a member rotatably mounted insaid bore and having a fingerpmanipulated knob at the outer end thereoycfor rotating said member, said mem ber carrying said movable abutmentsurface for moving the latter between said one and said other positionthereof upon rotation of said knob.

14. For use with a portable tool having a housing with atrigger-*receiving aperture, wherein the tool is of the type adapted touse a control system capable of varying the speed of the tool motor inresponse to the amount of trigger movement, a trigger actuated switchdevice for mounting in said tool with the trigger extending through saidaperture for manual depression, said switch device comprising, a casingand a trigger mounted thereby for oscillating movement, said device alsoincluding resilient means interposed between said casing and saidtrigger for urging the latter to its extended position, abutment meanscarried by said casing, adjustment means carried by said trigger andincluding an element adapted for abutting engagement with said abutmentmeans, said element being movable relative to the trigger by operationof said adjustment means thereby to vary the limit of trigger movementupon depression of the trigger.

References Cited The following references, cited by the Examiner, are ofrecord in the patented le of this patent or the original patent.

UNITED STATES PATENTS 3,378,662 4/1968 Sorenson 200-157 3,383,943 5/1968Piber 20D-157 X 1,712,261 5/1929 Farley 200--157 ROBERT S. MACON,Primary Examiner D. SMITH, JR., Assistant Examiner U.S. Cl. X.R. 74-527Notice of Adverse Decision in Interference In [utzm'fercnfe N0. 9759Knvnlvng Patent N0. Re. 26,781, J. Frenzel, TRIGGICR ACTU'IE) SW'ITUIIDEVICE, film] judgnwnt adverse t0 ille patentee was rendered Feb. 2:,1974,:15 to claim l-L. [Oficial Gazee A uga-st 5, 1.975.]

